A new variant of the pesky Sober worm led the top-10 list of viruses compiled by SophosLabs this May.

The Sober-N worm, which was detected in early May, spread rapidly across about 40 countries by promising it's recipients tickets to see the 2006 World Cup in Germany. It has managed to surpass the virus Zafi-D, which had dominated the virus charts for the past five months.

To add to the problem, the Sober-Q worm, which appeared mid-May, uses computers infected by Sober-N as zombie spamming machines to spit out neo-Nazi propaganda.

"This kind of virus-spam convergence have become commonplace", says SophosLabs, of Lynnfield, Mass.